Nonlocal photopolymerization kinetics including multiple termination mechanisms and dark reactions Part II Experimental validation

Extended model of the photoinitiation mechanisms in photopolymer materials

“…The excited singlet state can return to its ground state by radiationless energy transfer to another molecule such as triethanolamine, which acts as an electron donor ͑ED͒, and by the emission of a photon by fluorescence. 1,2,[4][5][6][7]12 We assume that these processes take place at an overall rate of recovery, r 1 . The resulting singlet state dye can also undergo intersystem crossing into the more stable and longer-lived triplet state, 1 …”

“…Since the primary radicals are generated in pairs, [2][3][4][5][6][7][8]16 the rate equation governing ͓ED͔ can be presented in the same fashion,…”

“…͑a͒ The first is the initiation of the polymerization process in the presence of monomer, [1][2][3][4][5][6][7] ED…”

“…͑b͒ The second reaction involves the free radical undergoing dye bleaching. [1][2][3][4][5][6][7]15,17 This occurs when the dye radical, see Eq. ͑4͒, abstracts the proton which the ED radical cation released at an earlier stage, see Eq.…”

“…[1][2][3][4] The resulting models attempt to take account of the effects of ͑i͒ the photon absorption, ͑ii͒ the regeneration or recovery of absorptive photosensitizer, and ͑iii͒ photosensitizer bleaching. In this paper, the photoinitiation mechanisms involved during holographic recording in a polyvinyl alcohol/acrylamide ͑PVA/AA͒ based photopolymer [5][6][7][8][9][10][11] is studied.…”